89 lines
1.4 KiB
Go
89 lines
1.4 KiB
Go
package wal
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import (
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"git.crumpington.com/public/jldb/lib/errs"
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"time"
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)
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type walIterator struct {
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// getSeg should return a segment given its ID, or return nil.
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getSeg func(id int64) (*segment, error)
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seg *segment // Our current segment.
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it Iterator // Our current segment iterator.
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seqNum int64
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err error
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}
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func newWALIterator(
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getSeg func(id int64) (*segment, error),
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seg *segment,
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fromSeqNum int64,
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) (
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*walIterator,
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error,
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) {
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segIter, err := seg.Iterator(fromSeqNum)
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if err != nil {
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return nil, err
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}
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return &walIterator{
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getSeg: getSeg,
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seg: seg,
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it: segIter,
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seqNum: fromSeqNum,
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}, nil
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}
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func (it *walIterator) Next(timeout time.Duration) bool {
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if it.err != nil {
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return false
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}
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if it.it.Next(timeout) {
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it.seqNum++
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return true
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}
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it.err = it.it.Error()
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if !errs.EOFArchived.Is(it.err) {
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return false
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}
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it.it.Close()
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id := it.seg.ID + 1
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it.seg, it.err = it.getSeg(id)
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if it.err != nil {
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return false
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}
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if it.seg == nil {
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it.err = errs.NotFound // Could be not-found, or closed.
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return false
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}
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it.it, it.err = it.seg.Iterator(it.seqNum)
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if it.err != nil {
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return false
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}
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return it.Next(timeout)
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}
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func (it *walIterator) Record() Record {
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return it.it.Record()
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}
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func (it *walIterator) Error() error {
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return it.err
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}
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func (it *walIterator) Close() {
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if it.it != nil {
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it.it.Close()
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}
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it.it = nil
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}
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